The present disclosure is broadly concerned with cofferdams for use in temporarily holding back a body of water when performing construction, repairs or bank stabilization in the bed of a river or a lake or any body of water, and also on dry land for flood protection. Such cofferdams are typically constructed of a framework of individual frame structures placed in adjacent alignment along a portion of the body of water which is to be held back. A flexible waterproof fabric is secured along the framework for holding back the water so that work may be performed in the area behind the framework. Given the substantial hydrostatic pressure created in holding back a large volume of water, the frame structures must be extremely sturdy. They are typically formed of steel or iron stock and have a triangular configuration which is best suited for bearing the pressure load. These cofferdams are constructed so that they may be quickly erected and disassembled. Portable dams of this type are well known to those having skill in the art.
Because of the need for quick assembly and disassembly of the portable dam, it is critical that the individual frame structures be configured not only for ease in erecting, but also ease and efficiency in transporting. Frequently, portable dams must be erected as quickly as possible, especially during emergency conditions, so it is important that the individual frame structures be connected in a manner to permit this. Current modes of connection include clamps which must be bolted directly to the frame structures, and stakes which must be driven into the ground as well as bolted to the frame structure. A substantial amount of time is invested in bolting on these clamps. Additionally, because of the large number of individual frame structures required in constructing a length of cofferdam, it is desirable to maximize the number of frame structures that can be stacked on a truck or trailer that transports the frame structures. Generally, individual frame structures are integral pieces and are fixed in their triangular configuration, which is not particularly conducive to efficient stacking. Accordingly, several truck load trips must usually be made to bring a sufficient number of frame structures to the cofferdam construction site.
A further problem faced by erectors of portable cofferdams lies in being able to place the framework down in a stable position in the bed of the body of water to be held back. There is a tremendous pressure placed on the frame structures from the body of water that is held back. Frequently, the river bed is uneven or rocky, which creates stability problems by causing the continuity of the framework to be disrupted. Weak points in the framework caused by such a disruption could allow the cofferdam to collapse, leading to disastrous results.
Accordingly, there is a need in the art for frame structures for use in a portable dam that are adapted for quick assembly and disassembly in erecting the dam with minimal amount of set up time or expenditure of manpower. Additionally, it is desirable that such frame structures be configured for efficient transportation and storage.
Further, there is a need for frame structures of a portable dam that provide stabilization for supporting large hydrostatic pressures and that are adapted to adjust to uneven terrain on which the dam is erected so that stability of the dam can be maintained.